Centrifugal mixing device



April 1953 1. Mom-:00 2,635,860

CENTRIFUGAL MIXING DEVICE Filed June 11', 1951 INVENTOR. IAN M LEOD,

fi TT RNEY Patented Apr. 21, 1953 GENTRIEUGAL MIXING nsvron Ian Mc eodGeneva N- ssi ns? t9 lirsmi r Mill Corporation, Geneva, N. Y., acorporation of New York Application June 11, 1951, Serial No. 230,863

Claims, (Cl. 259-996).

This invention relates to a centrifugal mixin device.

The principal object of this invention is the provision of a centrifugalmixing device which ape plies suction forces upon the fluid being mixedin two spaced areas. More specifically, the centrifugal mixing deviceherein claimed in a doubleended mechanism which provides a suctioneffect at both ends. In the normal course of operation of this mixingdevice, it is held in vertical position so that its lower end provides asuction effect upon the fluid at the bottom of the mixing vessel and theupper end provides a suction effect upon the fluid at the top ofthemixing vessel. Consequently, if the fluid has two components, one ofwhich is relatively heavy and the other of which is relatively light,the lower end of the mixing device will apply a suction force to theheavier component, which normally tends to settle to the bottom of themixing vessel, and the upper end of the mixing device applies a suctionforce to. the lighter component, which normally tends to. rise to thetop of the mixing vessel.

Another object of the present invention is the provision of adOllb1B+ndBd centrifu al mixing device of the character described,wherein each end is provided ith its own mixing chamber, the two mixingchambers. being in communication ith each other throug p ssa ways. whichlink them. It is by this means that the fluid drawn into the upper endof the mixing device is, itself thoroughly mixed and the fluid drawninto the lower mixing chamber is simultaneously thoroughly mixed andthen both mixtures are brought together and intimately intermingled. Theinvention is presented in several forms. In some of these forms thepassageways between the two mixing chambers are fixed dimensionally, butin one form they are adjustable so as to control the flow between thetwo mixing chambers.

The centrifugal mixing device herein claimed is very effective in manyapplications. Its double tion re r it t e s us and twi ev as sil ient.many p icat ns. as promo iona ins sv -t h Qeutr iusal mixing de i es.- Iis highly uit bl for mixin liquids of ifierent viscosit and. dif er ntsp c s ityt s g ly us l in mixing liquids which are relatively h avy andthick; it is equally useful in mixing liquids which are relatively thinand light in weight.

The p nt de i hi h y uit b e f r b en ins .colq s h i f mix n a d blnding color pas es an ds d h l ke Th double ac on o he pres nt ev cealso nder i hi hly su table fer romoti g d sired 2. chemical reactionswhich are intended to take place during mixing operations.

It will be understood that thisv mixing device is anpliuable not onlyto. fluids but also to solids in powder form. Thus, it may be used tomix two or more fluids and it may also be used to mix two on morepowders or a fluid and a powder. The present device is useful not onlyas a mixing device, butv also as a dispersing device where it is desiredto disperse one material or substance throughout another material orsubstance.

Preferred forms of this invention are shown in the accompanying drawing,in which:

Fig. 1 is a vertical section through a centrifugal mixing device made inaccordance with one form of the invention, said section being on theline I71! of Fig. 2.

l t-1g. 2 is a bottom end view thereof.

Fi 3 is another. section through a centrifugal mixer made in accordancewith a second form of his invention- Fig. a is still another sectionalview through a centrifugal mixer made in accordance with a third r ofthis. invention.

Fig, 5 is another section through a centrifugal mixer made in accordancewith a fourth form of this invention.

Fig. 6 is a sectional view through a centrifugal mixer made inaccordance with a fifth form of thisinvention,

Fig. 7 shows the centrifugal mixer of Fig. 3 in operative position in amixing tank filled with a fluid.

Fig. 3 s a view similar to that of Fig. 7 but showing a pipe leading toone end of the centrifugal mixer and a second pipe leading to theopposite, end thereof, both pipes carrying liquids to the centrifugalmixer for mixing purposes.

Referring now to the first form of this invention as shown in Figs. 1and 2, it will be seen that a, centrifugal mixin device In is providedwhich includes a rotatably mounted shaft l2 connected to an electricmotor M. The motor is mounted n a brac et 16 which is, in turn, swivellysup ported by a ramp 1 which may be mounted on the side wall of a mixingtank or vessel at. A sleeve 22 is secured to the lower end of shaft [2and a nut 2Q on said shaft prevents displacement Q d slodem nt of saidsleeve relative to said shaft. SliifiYQ 32 has an annular shoulder 26intermediate its ends for a purpose which will shortly appear. A.coneeshaped'cup 28 and a second coneshaped cup 30 are both mounted onsleeve 22 concentrically with each other and coaxially with said sleeveand with shaft 12; A web or wall 3'2 forms the base of cup 28 and acorresponding web 3 or wall 34 forms the base or floor of cup 30. Itwill be noted that the two bases 32 and 34 are juxtaposed so that as thetwo cups are situated in Fig. 1, base 34 constitutes the bottom wall orfloor of cup 36, and base 32 constitutes the upper wall or ceiling ofcup 28. An opening 36 is formed at the top of cup 30 and a correspondingopening 38 is formed at the bottom of cup 28 which may more precisely bedesignated as an inverted cup. The two openings 36 and 38 are inregistration with each other and they constitute the inlet openings ofthe mixing device as will hereinafter more fully appear. It will benoted that a center hole is formed in the two web or bases 32 and 34 toaccommodate sleeve 22, and hence the shaft on which said sleeve ismounted. Web or base 32 rests on annular shoulder 26 of the sleeve and alock ring 40 secures both webs or bases 32 and 34 to said sleeve 22. Theprecise mean used in anchoring cup 30 and inverted cup 28 to shaft 12are not critical and any suitable and conventional means may be used forthat purpose.

It will be seen that a plurality of radial openings 42 are formed in theweb or base 32 of inverted cup 28 and that corresponding openings 44 areformed in web or base 34 of cup 30. These openings 42 and 44 registerwith each other and they constitute the passageways'through whichcommunication is provided between the two cups. More particularly,communication is thereby provided between the inside of cup 28 which maybe designated as the lower mixing chamber 46 and the inside of cup 30which may be designated as the upper mixing chamber 48.

It will also be seen that a plurality of openings 50 are formed in theside wall of inverted cup 28 and it will be understood that these latteropenings constitute the outlet openings of the mixing device. Theseoutlet openings are formed in only one of the two cups and henceWhatever fluid enters both cups must pass through said outlet openings.In the case shown in the drawing, outlet openings 50 are formed in thelower cup 28 and hence such fluid as enters upper cup 30 throughopenings 36 must pass through openings 44 and 42 in order to make itsway to the outlet openings 50.

It is important to note the overall shape of the two cups. It will beseen that each cup is tapered or cone-shaped. Its base is relativelylarge and the opening opposite the base is relatively small so that eachcup may be described as resembling or constituting a truncated cone.When the two cups are juxtaposed as shown in Fig. 1, they form a unitwhich resembles two truncated cones placed base to base in coaxialrelation to each other. This overall shape is, of course, merelypreferred and other shapes may be provided Within the broad principlesof the invention. Witness the other forms of the invention shown in thedrawing.

The operation of the centrifugal mixing device last above described isclearly shown in Fig. 7, although the precise construction of Fig. 1 isnot carried over into Fig. 7. It will there be noted that the shaft I2is supported in vertical position and that the two cups, which maycollectively be described as the mixing head of the device, are immersedin a fluid '52 contained in mixing tank or vessel 20. As the mixing headrotates in the direction of the arrow in Fig. 1, fluid A enters theupper chamber and fluid B enters the lower mixing chamber throughopenings 36 and 38, respectively. The fluid A which enters the uppermixing chamber passes through the passageways between the two mixingchambers in order to enter the lower mixing chamber where it mixes withthe fluid B which enters the lower mixing chamber through the loweropening 38. The mixed fluids AB are then thrown out of the lower mixingchamber through openings 50 in its side wall, this action taking placeunder the influence of centrifugal force generated by the rotatingmixing head. The process continues until the fluid or fluids, as thecase may be, is or are thoroughly mixed in the mixing tank.

Fig. 8 shows the apparatus of Fig. '7 with three additional elements: afluid feeding pipe 66, a second fluid feed pipe 82, and an outlet pipeor nozzle 64. Feeding pipe Bil is so situated that its outlet end feedsdirectly into the upper mixing chamber of the centrifugal mixer. Thesecond fluid feeding pipe 62 is so situated that its outlet end feedsdirectly into the lower mixing chamber of the centrifugal mixer. Hence,the mixer is enabled to mix the two fluids before they flow into' themixing tank 66. The two fluids C and D are mixed together to form asingle mixture CD at the time they are caused to leave the lower mixingchamber through the side openings formed in the side wall thereof. It isthe mixed fluid CD which flows out of the tank through outlet pipe ornozzle 64.

It will, of course, be understood that the centrifugal mixer abovedescribed may be provided,

and preferably is provided, with a pair of vanes 58 extendingdiametrically across the two mixing chambers on a common vertical plane,as

viewed in Figs. 1 and 2.

' fluid to rotate therewith. This has the effect of emphasizing andamplifying the centrifugal action upon the fluid so as to'enhance themixing action.

The centrifugal mixer 70 shown in Fig. 3 is similar in principle to themixer shown in Figs. 1 and 2 except that its two cups are integral witheach other and with'the further exception that it is mounted directlyupon shaft 12 instead of upon a sleeve which is mounted on the shaft.The centrifugal mixer shown in Fig. 3 corresponds to the mixer shown inFigs. 7 and 8, and it may be described as comprising an upper cup 14 anda lower cup 16 which have a common base or end wall 73. These two cupsare cone-shaped as above described, their open ends 80 and 82, re-'spectively being smaller than their base 18. Openings 84 are formed inbase 18 to provide communication between the upper mixing chamber 86 andthe lower mixing chamber '88. Openings 90 formed in the side wall of cup16 are the outlet openings through which the mixed fluid is thrown outof the lower mixing chamber by centrifugal force. The operation of thiscentrifugal mixer has above been described in connection with Figs. 7and 8. Here, too, a pair of vertically extending vanes 92 are preferablyprovided so as to enable the mixer to carry the fluid around in a rotarypath in the two mixing chambers and thereby to enhance the mixing actionand to amplify the centrifugal force which is exerted upon the fluid.

Centrifugal mixer I30 shown in Fig. 4 differs only slightly from themixer shown in Fig. 3. It will be noted that the two cups Hi2 and H14are integral with each other since they have. a common base N36. Theupper cup I02 is coneshaped in the manner above described. The lower cupI04, on the other hand, has a cylin- I08. The upper cup I02 also has aninlet opening. I-IIl which corresponds to the inlet, opening- I08. ofthe lower cup. In this construction, lower mixing chamber '2 isconsiderably larger than the upper mixing chamber H4 and the advantageis apparent from the fact that the. lower mixing chamber I I2 receivesfluid. not onlyfrom its own inlet opening I08 but also from the uppermixing chamber H4: through communicating passages IIB in base I06. MixerI may also be provided with vertically extending vanes IIB to assist inthe mixing action. It may here be stated, that these vanes may also beemployed for the additional purposes of properly securing the mixinghead to the shaft.

Centrifugal mixer I20 shown in Fig. is very similar to centrifugal mixerI00 shown in Fig. 4, except that the cylindrical portion I22 of itslower cup I24 projects radially outwardly so as to provide added mixingspace in its lower mixing chamber I26. It will be noted that the outletopenings I20 of both centrifugal mixers I00 and I20 are provided in thecylindrical portion of the lower cup rather than in its cone-shapedportion. It will be understood that the greater the diameter of thecylindrical portion wherein the outlet openings are formed, the morepowerful will be the centrifugal force upon the fluid, all otherconditions being equal.

In Fig. 6 centrifugal mixer I30 is shown. Here lower cup I32 is integralwith shaft I34 and upper cup I36 is integral with sleeve I38 on saidshaft. The shaft is provided with screw threads I40 and with a nut I42thereon. It will be understood that sleeve I3'8 is movable angularlyrelative to shaft I34 and that nut I42 is provided to fix the relativepositions of said sleeve and said shaft. It will be noted that openingsI 44 are formed in the base I46 of cup I36 and that correspondingopenings I48 are formed in the base I50 of cup I32. These openings I44and I48 may be made to register with each other either wholly or in partdepending upon the relative positions of the two cups. Hence the amountof flow from the mixing chamber I52 to the mixing chamber I54 may becontrolled by changing the relative positions of the two cups and thenfixing them in place relative to each other by means of nut I42. Outletopenings or slots I5I are provided in the conical wall of the lowermixing chamber.

It will be understood that the foregoing is descr'iptive of preferredforms of this invention.

These forms may be modified in many ways and other forms may be providedwithin the broad scope and spirit of the invention and of the claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. A centrifugal mixing device, having a vertically extending,rotata-bly mounted shaft, 2. hollow housing secured to the lower end ofsaid shaft, said hollow housing being open at the top and at the bottom,a horizontal partition in said hollow housing extending from wall towall thereof and dividing it into upper and lower mixing chambers,openings formed in said horizontal partition to provide communicationbetween said upper and lower mixing chambers, and a plurality ofopenings formed in the side of said hollow housing entirely on one sideof said partition for communication between the outside of said housingand only one of said mixing; chambers.

2. A centrifugal mixing device having a veritiw cally extending,rotatably mounted shaft. a hol low housing secured: to the lower end of;the shaft, said hollow housing being open at. the too and. at the bottomand being provided with. a horizontal partition which extends from wallt wall thereof and divides it into upper and lower mixing chambers,openings. formed in said horizontal partition to. provide communicationbetween said: mixing chambers, and a plurality of openings formed in theside wall of said hollow housing below said horizontal partition, to.pro vide communication between the lower mixing chamber and the outsideof the hollow housing.

3. A centrifugal mixing device having a vertically extending rotatablymounted shaft, a hollow housing having an inlet opening at the top andan inlet opening at the bottom, a horizontal web formed on the inside ofsaid hollow housing extending from wall to wall thereof and securingsaid hollow housing to the lower end of said shaft, openings formed insaid horizontal web to provide communication between the inside of saidhollow housing above the web and the inside of said hollow housing belowthe web, said housing having a plurality of outlet openings extendingthrough the side wall thereof below said web to provide communicationbetween the inside of the hollow housing below said web and the outsideof said hollow housing.

4. A centrifugal mixing device having 'a tubular housing which is openat the top and bottom, a horizontal partition in said tubular housingwhich divides it into upper and lower :mixing chambers, a verticallyextending, rotatably mounted shaft which is secured at its lower end tosaid horizontal partition, a plurality of openings formed in saidhorizontal partition to provide communication between the upper andlower mixing chambers, said housing having a plurality of openingsextending through the side wall thereof, below said horizontalpartition, to provide communication between the lower mixing chamber andthe outside of the tubular housing.

5. A centrifugal mixing device in accordance with claim 4, wherein thetubular housing is conically tapered inwardly at its upper and lowerends so that its upper mixing chamber is relatively small at the top andrelatively large at the bottom and its lower mixing chamber isrelatively small at the bottom and relatively large at the top.

6. A centrifugal mixing device comprising a cone-shaped cup which isopen at the top, a cone-shaped cup which is open at the bottom, the twocups being arranged coaxially with their bases facing each other,passageways formed between the two cups to provide communicationtherebetween, openings formed in the side wall of only one of said cups,and a. rotatably mounted shaft secured to both cups, coaxiallytherewith.

7. A centrifugal mixing device comprising a pair of cone-shaped cups,each having a relatively broad base and a relatively small openingopposite the base, said cups being secured coaxially to each other attheir respective bases, openings formed in said bases to providecommunication between the two cups, a plurality of openings formed inthe side wall of only one of said cups, and a rotatably mounted shaftsecured to the bases of the two cups coaxially therewith.

7 8. A centrifugal mixing device in accordance with claim 7 wherein oneof said cups is angularly adjustable relative to the other cup so as toadjust the sizes of the openings in the bases of the two cups andthereby to control communication therebetween.

9. A centrifugal mixing device in accordance with claim 7, whereinvertical extending vanes are provided in the two cups. 7

10. A centrifugal mixing device in accordance 10 with claim 6 whereinmeans are provided for varying the size of the openings in the bases ofthe two cups and thereby to control communication therebetween.

IAN McLEOD.

References Cited in the file of this patent UNITED STATES PATENTS NumberNumber Name Date 'Groch Oct. 15, 1918 Greenwalt Apr. 12, 1921 GreenwaltFeb. 17, 1925 Schonelborn Mar. 6, 1934 Underwood Aug. 26, 1941 ChilsonApr. 20, 1943 FOREIGN PATENTS Country Date Great Britain Jan. 21, 1932Germany Oct. 2, 1929,

